Drug Interaction Report

Erythromycin may significantly increase the blood levels of ivacaftor from certain formulations. This may increase the risk and/or severity of serious side effects such as liver damage. A dosage adjustment may be required. Talk to your doctor if you have any questions or concerns, or if you do not know whether your dosage has already been adjusted. Call your doctor immediately if you have fever, chills, joint pain or swelling, unusual bleeding or bruising, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, abdominal pain, dark urine, pale stools, and/or yellowing of the skin or eyes, as these may be signs and symptoms of liver damage. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Food decreases the levels of erythromycin in your body. Take erythromycin on an empty stomach at least 30 minutes before or 2 hours after a meal. This will make it easier for your body to absorb the medication. However, some erythromycin products may be taken without regard to meals. Ask your healthcare provider about your particular prescription if you are uncertain of how to take it. Grapefruits and grapefruit juice may increase erythromycin levels but how this may affect you is not known. Do not increase or decrease the amount of grapefruit products in your diet without first talking to your doctor.

Ivacaftor should be taken with fat-containing foods such as eggs, avocados, nuts, meat, butter, peanut butter, cheese pizza, and whole-milk dairy products to help with its absorption. Do not consume grapefruit juice or any food that contains grapefruit or Seville oranges during treatment with ivacaftor unless directed otherwise by your doctor. Grapefruit juice can significantly increase the blood levels of ivacaftor. This may increase the risk and/or severity of serious side effects such as liver damage. Call your doctor immediately if you have fever, chills, joint pain or swelling, unusual bleeding or bruising, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, abdominal pain, dark urine, pale stools, and/or yellowing of the skin or eyes, as these may be signs and symptoms of liver damage. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Information for this minor interaction is available on the professional version.